Controller for electric motors.



No. 758,610. PATBNTBD MAY 3, 1904.

' T. B; BARNUM.

CONTROLLER FOR ELECTRIC MOTORS. APPLICATION FILED FEB. 7, 1902.

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W gg 7 MWS UNrrnn STATES Patentecl lliay s, 1904.

ATENT Fries.

THOMAS E. BARNUM, OF MILWAUKEE, W ISCONSIN, ASSIGNOR TO THECUTLER-HAMMER MANUFACTURING COMPANY, OF MILWVAUKEE, IVISCONSIN, ACORPORATION OF WVISCONSIN.

CONTROLLER FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 758,610, dated May 3,1904.

Application filed February '7, 1902. Serial No. 93,046. (No d l.)

To all whmn it may concern:

Be it known that LTHoMAs E. BARNUM, a citizen of the United States,residing at Milwaukee, in the county ofMilwaukee and State of Wisconsin,have invented a certain new and useful Improvement in Controllers forElectric Motors, of which the following is a full, clear, concise, andexact description, reference being had to the accompanying drawing,forming a part of this specification.

My invention relates to a controller for electric motors, the objectbeing to provide means for operating the motor at a slow speed andstopping and starting the same from a distant point or points.

It is frequently desirable with certain classes of machinery, as withprinting-presses, to operate the same at a slow speed and to stop andstart the same from points about the press or other machinery. Such anoperation of a printing-press is termed inching. For this purpose Iaccordingly place switches at any desired points about the machine whichare adapted when suitably actuated to stop and start the motor,providing the same is operating at a slow speed and a large part of themotor resistance is still in the motor-circuit; but when the motor isoperating at the normal speed or near the normal speed and theresistance is nearly or all cut out of the circuit the arrangement issuch that the switches can then be used only for stopping the press,whereby there is no liability of damage to the motor or other parts bythe attempt to start the motor when the resistance of the motorrheostatis all cut out.

My invention will be readily understood from the accompanying drawing,in which the figure is a diagram showing the circuit connections.

The contact-arm 20f the motor resistance 3 is adapted to be moved overthe segments or terminals 4, the said arm being connected with one side5 of the supply-circuit. The end of the resistance 3 is connected byconductor 6 through the armature of the motor 7 and thence by conductor8 with the contacts 9 9, which are adapted to be bridged by the contact10 to the other side of the supply-circuit 11. The shunt-coil 12 of themotor is connected between the conductor 8 and the supply-conductor 5.

The contact-arm 2 carries a brush 13, initially resting upon adead-contact 14, adapted to travel over a contact 16, the latterencircling only a portion of the resistance, while the remainder 17 ofthe contact is not in connection with the wiring of the circuit. The

contact 16 is connected, through the medium of a conductor 18 and.parallel branch terminals 19 19 19, with contacts 2020 20, mounted uponswitches 21, 22, and 23. These switches are each provided with twoadditional contacts, the contact on the other side of the switch beingentirely disconnected, and therefore dead, while the center contact 2 1of switch 21 is connected, by means of aconductor 25, through theresistance-lamps 26 to the supply-conductor 5. The switch-arm 27 ofswitch 21 is connected, through conductor 28, with the contact 24 ofswitch 22, and the arm of the latter switch is connected by a similarconductor 29 with the like contact 24: of the switch 23, the arm 27 ofthe latter being connected through conductor 30, through solenoid-magnet31, to the contacts of the overloadswitches 32, to the contact 9, andthe side 11 of the supply-circuit. The solenoid 31 acts to bridge thecontacts 9 9 together by means of the contact 10, and theoverload-switch 32 prevents injury to the parts by an abnormal currenton the main.

Normally the parts arein the position shown in the drawing. When it isdesired to operate the machinery driven by the motor 7 at a slow speedfor inspection, repair, or other purposes, and to stop and start thesame from a distant point or points in the neighborhood of themachinery, as at the switches 21, 22, and 23, the contact-arm'2 is firstmoved clockwise, so that the brush 13 contacts with the curvedcontact-strip 16 and is set in such a position that the amount ofresistance left in circuit will allow the motor to start the mechanismpromptly and readily. To start the -motor from any of the switches 21,22, or 23,

the contact-arm 27 of any of said switches is moved clockwise, so as tocontact with contact 20, as shown in dotted lines at switch 21. Thecircuit then completed from the conductor 5 through the contact-arm 2,brush 13, contact-bar 16, conductors 18 and 19, contact 20, and arm 27of switch 21, thence through the conductor 28, contact 24:, and arm 27of switch 22, and so on through switch 23 to the conductor 30 andthrough the solenoid-coil 31, through conductor 30 and the contacts ofthe overload-switch 32 to contact 9 of the solenoid 31, thence throughthe magnet of the overload'switch 32 to the other conductor 11 of theswitch-circuit. The solenoid is thus energized and lifts the contact 10to bridge contacts 9 9 together and complete circuit through theshunt-coil 12 of the motor, as well as through the armature 7 thereof,the latter circuit including the resistance 3, between the contact-arm 2and the end thereof. The speed of the motor 7 and the machinery operatedthereby is thus determined by the amount of the resistance 3 in itsarmature-oircuit. The switch-arm 27 of switch 21 may now be placed uponcontact 2 T, but may be returned thereto by suitable automatic means,which I consider preferable, this being the normal position of arm 27.hen the switch-arm 27 is on contact 24, the circuit is closed from thesupplyconductor 5 through the resistance-lamps 26 and conductor 25through the several switches and the solenoid-coil, the resistance ofthe lamps being such as to cut down the consumption of the current inthe solenoid-coil and at the same time permitting the same to retain itscore in attracted position. When the motor is thus operating at thedesired slow speed, the same may be started and stopped at any of theswitches 21, 22, and 23, which may be conveniently placed about thepress or other machinery by merely moving the arms off the contacts 24in the direction of the dead-contacts. This of course will open thecircuit through the coil 31, when the contact 10 will drop and open thecircuit through the motor, thus causing it to stop. The motor may againbe started at the switch by moving the contact-arm 27 into engagementwith contact 20, which will serve to complete the circuit from thecurved contact-bar 16 through conductors 18 and 19, conductor 30, andthrough the coil 31, thus causing it to close the circuit throughcontacts 9 9 and 10. It will thus be seen that the motor may be operatedat any desired slow speed and started or stopped from any of theswitches without returning to the motor resistance 3 and withoutchanging the arm 2 thereof.

\Vhcn it is desired to operate the motor at its normal speed, thecontact-arm 2 is moved to its limit, thus cutting out all of theresistanee 3, and the switch-arm 27 of the switch 21 is placed upon thecenter contact 2%. U nder this condition the motor will operate at itsnormal speed, and while it may be stopped from any of the switches 21 2223 it cannot be again started without returning the arm 2 of the motorresistance to its initial position, for the reason that the conductor19, parallel branches 19, and the contacts 20 of the several switchesare entirely out of circuit. It will be understood that this normalspeed of the motor may be attained at once by moving the contact-arminto engagement with the contact-bar 16, then changing the arm 27 of theswitch 21 to the contact 24:, and then continuing the movement of thearm to its limit.

The number of switches 21 22, &c., may be varied as desired, and theymay be located at convenient points. Other arrangements andmodifications may also be made, and I therefore do not wish to belimited to the exact construction shown.

What I claim, and desire to secure by Letters Patent, is-

1. Thecombination with a motor, of a rheostat therefor, and a pluralityof switches connected in series and situated at a distance from saidrheostat for stopping and starting the motor independent of therheostat, substantially as described.

2. The combination with a motor, of a rheostat therefor, and a pluralityof switches connected in series and situated at a distant point forstopping and starting the motor ind ependent of the rheostat while it isrunning at less than normal speed, substantially as described.

3. The combination with a motor, of a rheostat therefor, and a pluralityof switches connected in series and situated at a distance from saidrheostat for stopping and starting the motor when it is running at aspeed below the normal, said starting and stopping being independent ofthe rheostat, substantially as described.

4. The combination with a motor, of a rheostat therefor, a plurality ofswitches connected in series and. located at a distance from therheostat, and means for stopping and starting the motor from any of saidswitches, said means beingindependent of the rheostat, substantially asdescribed.

5. The combination with a motor, of a rheostat therefor, a plurality ofswitches connected in series and located at distant points, and meansfor stopping and starting the motor from, any of said switches when itis operating at less than the normal speed, said means being independentof the rheostat, substantially as described.

6. The combination with a motor, of a rheostat therefor, a plurality ofswitches connected in series and situated at a distance from saidrheostat for stopping and starting the motor from a distant point when aportion of the resistance of the rheostat is in circuit, and means forpreventing the starting of the motor from such point, when all or agreater portion of resistance is cut out of circuit, substantially asdescribed.

7. The combination with a motor, of a rheostat therefor having a contactadapted to be engaged by the rheostat-arm during the first part of'itsmovement, a plurality of switches connected in series and placed at adistant point and connected with said rheostat-contact, and means forstarting and stopping the motor from said switch while the rheostat-armengages said contact, substantially as described.

8. The combination with a motor, of a rheostat therefor having anauxiliary contact adapted to be connected with the rheostat-circuitwhile a portion only of the resistance of the rheostat is in themotor-circuit, a plurality of switches connected in series placed at adistant point, and means for starting and stopping the motor from saidswitches while the said auxiliary contact is in circuit, substantiallyas described.

9. The combination with a motor, of a rheostat therefor, a circuitcontrolling the said motor, a switch located at a distant point in saidcircuit, parallel branches of said circuit controlled by said switch,one of said branches being controlled through the said rheostat and theother being independent of the rheostat, substantially as described.

10. The combination witha motor,of a starting-rheostat therefor, acircuit controlling the continuity of the motor-circuit, a switchlocated at a distant point in said first-named circuit, said first-namedcircuit having parallel branches controlled by said switch, one branchbeing independent of the rheostat and of high resistance, the otherbranch being operated through contacts of the rheostat and of lowresistance, substantially as described.

11. The combination witha motor, of arheostat therefor, anelectrically-operated switch controlling the motor-circuit, a switchremote from the rheostat, and means for causing the energization ordeenergization of the magnet of the electrically-operated switch fromsaid remote switch, said means being in series with the switch remotefrom the rheostat, substantially as described.

12. The combination with a motor, of arheostat therefor, anelectrically-operated switch controlling the motor-circuit, a switchremote from the rheostat, and means for opening and closing the saidcontrolling-switch from the remote switch, said means being in serieswith the switch remote from the rheostat, substantially as described.

13. The combination with a motor, of arheostat therefor, a switchindependent of the rheostat for controlling the motor circuit, and meansfor opening and closing said switch from a remote point, said meansbeing in series with the switch independent of the rheostat,substantially as described.

14. The combination with a motor, of an electrically-operated switch forcontrolling the circuit of the motor, and a switch for sending anenergizing-current or a retainingcurrent through the magnet-coil of saidcontrolling-switch, or for depriving the same of operating-current,substantially as described.

15. The combination with a motor, of a rheostat therefor, anelectrically-operated switch for controlling the circuit of the motor, aswitch remote from the above-named devices and adapted to sendoperating-current or retaining-current through the coil of said c0ntrolling-switch or for depriving the same of current, substantially asdescribed.

16. The combination with a motor, ofa rheostat therefor, and a pluralityof switches connected in series and situated at a distance from saidrheostat for stopping and starting the motor independent of therheostat-arm when said arm is in certain positions, sub stantially asdescribed.

17. The combination with a motor, of a rheostat therefor, and aplurality of switches connected in series and situated at a distantpoint for stopping and starting the motor while it is running at lessthan normal speed and when the arm of said rheostat is in certainpositions, substantially as described,

18. The combination with a motor, of a rheostat therefor, and aplurality of switches connected in series and situated at a distancefrom said rheostat for stopping and starting the motor independent ofthe rheostat-arm when it is in certain positions, substantially asdescribed.

19. The combination with a motor, of a rheostat therefor, and aplurality of switches connected in series and situated at a distancefrom said rheostat for stopping and starting the motor when it isrunning at a speed below the normal, said starting and stopping beingindependent of the rheostat-arm when it is in certain positions,substantially as described.

20. The combination with a motor, of a rheostat therefor, a plurality ofswitches connected in series and located at a distance from the motor,andmeans for stopping and starting the motor from any of said switches,said means being independent of the rheostat when said arm is in certainpositions, substantially as described.

21. The combination with a motor, of a rheostat therefor, a plurality ofswitches connected in series and located at adistant point, and meansfor stopping and starting the motor from any of said switches when it isoperating at less than normal speed, said means being independent ofvthe rheostat-arm when it is in certain positions, substantially asdescribed.

22. The combination with a motor, of an electrically-operated switch forcontrolling the circuit of the motor, and a plurality of switchesconnected in series for sending an energizing-current or aretainingcurrent through the magnet-coil of said controllingswitch,substantially as described.

23. The combination with a motor, of a rheostat therefor, anelectrically-operated switch for controlling the circuit ofthe motor,par allel branch circuits, a resistance arranged in one of said branchcircuits and a switch located at a distant point for connecting thesolenoid of the electrically-operated switch in either of said branchcircuits.

24. The combination with a motor, of a rheostat therefor, anelectrically-operated switch for controlling the circuit of the motor,parallel branch circuits, a resistance arranged in one of said branchcircuits, and a plurality of switches located at distant points forconnecting the solenoid of said electrically-operated switch in eitherof said branch circuits.

25. The combination with a motor, of a rheostat therefor, anelectrically-operated switch for controlling the circuit of the motor,parallel branch circuits, a resistance arranged in one of said branchcircuits, means connecting one side of the other branch circuit with thesupply-circuit when the rheostat is operated to start the motor and aswitch located at a distant point for connecting the solenoid of theelectrically-operated switch with either of said branch circuits.

26. The combination with a motor, of a rheostat therefor, anelectrically-opcrated switch for controlling the circuit of the motor,parallel branch circuits, a resistance arranged in one of said branchcircuits, a contact carried by the rheostat-arm connecting one side ofthe other branch circuit with the supply-circuit when the rheostat isoperated to start the motor, and a plurality of switches located atdistant points for connecting the solenoid of the e1ectrically-operatedswitch in either of said branch circuits.

27. The combination with a supply-circuit, of a motor connected therein,a rheostat for said motor, branch circuits leading from saidsupplycircuit to a magnetically operated switch for controlling thecontinuity of the motor-circuit, resistance arranged in one of saidbranch circuits, a contact carried by the rheostat-arm for connectingone side of the other branch circuit with the supply-circuits when therheostat is operated to start the motor and a switch located at adistant point for connecting the winding of said magneticallyoperatedswitch in either of said branch circuits.

28. The combination with a motor, of a rheostat therefor, having asupplemental contact adapted to be engaged by the rheostat-arm duringthe first part of its movement, a plurality of switches connected inseries and located at distant points, each switch having a contactconnected with said. rheostat-contact, a second contact connectedthrough a suitable resistance with one side of the main circuit, and acontact-arm connected through a solenoid-switch with the opposite sideof the main circuit.

29. The combination with a motor, of a rheostat therefor, having asupplemental contact adapted to be engaged by the rheostat-arm duringthe first part of its movement, a plurality of switches located, atdistant points, each switch having a contact connected with saidrheostat-contact, one of said switches having a second contact connectedthrough a suitable resistance with one side of the main circuit and anarm connected with a second contact on a second switch, said switchbeing in like manner connected with the next switch, and the arm of thelast switch being connected through a solenoid-switch with the oppositeside of the circuits.

In witness whereof I have hereunto subscribed my name in the presence oftwo witnesses.

THOMAS E. BA RNUM.

\Vitnesses:

NICK. EwENs, J. H. VVIE'RSUM

